Fluid suspension unit



April 18, 1961 F. F. TlMPNI-:R ETAL 2,930,441

FLUID SUSPENSION UNIT 2 Sheets-Sheet 1 Filed NOV. 28, 1958 Im. S w Nm. S .S S, T N nmw MII.. QN UIN l ...www mw RN QM. ww. Si www E S. IHF .QI :t \N\ w A mm. .S Sw

April 18, 1961 F. F. TIMPNER ETAL 2,980,441

FLUID SUSPENSION UNIT Filed Nov. 28, 1958 2 Sheets-Sheet 2 02122 @ego/fall BY Car/ J. f77/#ef Unite States Patent Il@ FLUID SUSPENSION UNT Filed Nov. 28, 1958, Ser. No. 776,781 11 Claims. (Cl. 280--124) This invention relates to a suspension system lfor a motor vehicle, and more particularly to a suspension system that uses a iluid spring, or an air spring, between the sprung mass and the unsprung mass of the vehicle to support the sprung mass upon the unsprung mass.

In suspension systems for motor vehicles that utilize an air spring for supporting the chassis relative to the running gear, it has been the practice to place the air spring between the chassis and the running gear so that the air spring performs the function of spring support of the sprung mass on the unsprung mass of the vehicle. The shock absorption system has been retained separate from the air spring with the shock absorber unit, in effect, being placed in parallel arrangement with the air spring, opposite ends of the shock absorber being connected to the sprung mass and the unsprung mass to provide for the desired absonption of road shock created by the running gear in operating under normal road conditions. Thus, the uid spring, or the air spring, performs its normal function of providing for resilience of suspension between the sprung mass and the unsprung mass and the shock absorber independently performs its function -of absorbingthe road shocks and controlling the rebound ofthe sprung mass relative to the unsprung mass. 1

It is desirable from a standpoint of design and production economy,- asxwellas space economy, to combine the uid spring Iwith the shock absorber. With the'V air spring and the shock absorber construction and arranged as a unit assembly for placement between the sprung mass and the unsprung'mass of the vehicle, production economies can be obtained by simplification of Vthe-de :s'ignl of wheel structure by the elimination of dual mounting requirements of the previously arranged separate units of air springend shock absorber. 4.

'However, there are certain diiculties in combining theshock absorber withv Vthe air springs to obtain a'unit arrangementin that there are transverse orlateral thrusts Vdeveloped Within the air spring in its normal operation on a motor vehicle which are transferable to/the shock absorber when the shock absorber is incorporated within the air spring and a part of the shock absorber is used 4as one of the mounting'elements for supporting a part thrusts developed'within the air spring are.note trans'- ferable directly to the shock absorber, but. rather are accepted by a, resilient structure positioned -between the 'thechassis frameand of the undercarriage fortheV4 shockabsorber and the air spring so that the resilient f" structure absorbs the transverse orlateral .thrusts created by the airV spring on the vshock absorber.` t The arrangement VisV such., thereforeQthatthe conventional piston and cylinder `typefof shock absorber, that is a direct-acting type, .is Ycapa'l'nle of;rbeing` usedjas at least one of the mounting membersV for supporting the air spring between the sprung mass and the unsprung mass of the vehicle, the elimination or reduction of lateral or transverse thrusts on the shock absorber avoiding high friction in the movement of the piston within the clyinder of the shock absorber It lis another object oft-he inventionnto provide an air spring incorporating a shock labsorber as an integral part thereof wherein the shock absorber is placed Within the interior of the air spring, that is within the air chamber of the air spring, with the shock absorber having one end thereof attached to a stationary wall of the air spring and the opposite end ofthe shock absorber extending through a movable wall of the air spring with the said opposite end of the shock absorber providing the mounting means for supporting the air spring' on thevehicle structure. In this arrangement ofthe combined air spring and shock absorber, the shock absorber extends through a movable wall of the air Aspring with the movable wall being supported by the shock absorber, a resilient pad of material being positioned between the movable wall and the shock absorber to allow for resilience of movement of the movable wall of the air spring relative to the shock absorber to reduce or prevent'transfer of transverse or lateral thrusts from the `movabl`e absorber consists of a rubber-like or elastomeric material which also provides a seal between the movable wall and the shock absorber' to prevent escape of fluid pressure from within the air spring.

Further objects and advantages of theV present invention will bey apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown. l Y,

In the drawings:

Fig. l is' a side vien/,partially in elevation and partially in cross section, of a suspension structure incorporating Vthe combined air spring and shock absorber of this invention. I

Fig. l2 is a transverse cross-sectional view of the shock absorber and air spring taken along line 2 2 of Fig. 51.

Fig. 3 is a transverse cross-sectional view of the combined 'air spring and shock absorber taken along line 3-3V of Fig. 1. l

-In Figfl thereis illustrated a' part of a motor vehicle that includes ja chassis framelt) disposed at the` forward i end of the vehicle. A steering knuckle 11 is supported upon the chassis member 10 by means of a lower control arm 12 that has one end thereof in pivotal connection withl the chassis frame 10 by means of the pivot connection 13. The opposite end of the lower controlarm connects with the steering knuckleythrough a spherical or ball joint 14. -The steering knuckle V11 is connected by means of a spherical joint 15 Withthe upper control arm 16 that, in turn, Vis pivotally connectedwith the chassis frame 10 with a pivot connection much like the member 13. I l p Aair spring 2D that includes a shock absorber 25' is 'f positioned between the chassis frame y10 ,and then-lower' control armV 12 thereby providing for a resilient Yshock absorbing supportof theunsprung mass `of the vehicle cornp'risingthe wheel support structure 12, 11 Tand 16 l tionary with the cha -tainer 21. The cicible V'12, in a manner hereinafter'described. The outer Y.pressen-inetV shown, ,driven by the y 'I'he'shockfabsorber upperV stationary wall 22 and a lower movable wall 23,

more specifically described hereinafter. The container 21is suitably secured to the chassis frame 10 and thereby forms a stationary part of the air spring that is stassis'frarne 10. f The rlower ymovable' wall 23 comprises a. piston e'lement l24- Vand a flexible diaphragm 'element'26 that connects the piston element V24 with the open end 27 of the stationary `can orjcontainer 21.' The diaphragm 2 6 is preformed peripheral end ofthe piston-member 2 3'and an outer peripheral edge 29 that is-suitably'secured to the open end 27 of the con- Y i diaphragm 26 therefore allows piston member 23V into and out of the by the'container 21 on relative move- Vmovement of the `chamber formed "ment between-the control yarms 12 and 16 relative to the chassis frarnelU.

vThe-piston member 23 has an axial opening 30 through which the 'shock' absorber 25 extends for attachment to a support member 31 secured to the lower'control arm Y i periph- Vment of the piston into and out of the container 21,*the vcontour of thepiston -23beingsuch as to provide for increased resistance to compression of theair spring as the control YYYarml 12 moves upwardly: toward the chassis frame10.l"-

i -Thecontainer 21 receives air under. pressure from a Vsuitable source of supply, `such as a reservoir, notV shown, carried on the vehicle, the reservoir being supplied with in the general form of a torous having an inner` edge -28 that issuitably'securedlto the upper The piston 36 is provided with resi-stance valving 51 on the upper face thereof and other resistance valving 50 ya mounting ringV 55 that is suitably supported upon a air under pressure and maintained at a predetermined pressure :value within the reservoir by means of a cornengine of the vehicle.

Theairy under pressure from the reservoiris supplied tov Y -aY suitable control` valve that responds to a change in y vclearance height between the sprung-mass and the `un sprung massofthe vehicle, thatis between the body and the running gear, to 'eitheradd airunderpressure into the container nZIWhen-the load inv the vehicle increases or Y 1to Aexhaust lair from within thecontainerZl; when the load V,within thegvehicledecreases. Such controlvalves Vfor, acvcomplishingrthis purpose are now known in the artv and it is believed'no further'description ofsuchV valves need begmade vv since the valvegperysejand the'spectic control of the air tor-and, from theair spring forms no part ofthis particu-laiinvention.

der receiving Vapiston 36 reciprocable within thecylinder; Tghepiston 3 6 is connected with-anoperating rod @The shockl absorber cylinder lis `contained,within'ann 36 away fromY the base valve to al 2 5'is amore orless conventional typeof `direct-acting.shock absorber that includes 'a cylinmounting stud 56 carried' on the support 31. The shock absorber thus Vhas its opposite ends connected withthe stationary wall 22`of the air spring ZtlfandV the lower control arm 12 of the wheel support system rso that road Vshocksoccurringto the wheel'system willjbe absorbed by the sho'ck absorber in transfer to the chassis frame 10. Thus, the lshock @absorber perorms its usual function of absorbing the road shock during the compression'stro'ke of the shock Yabsorber andfcontrolling the rebound of the chassis frame in the opposite Ydirection.'`

The outer cylinder-42 of the shook absorber- 25 carries an annular seat member() secured rigidlythereto such asV by a welding operation. The seat member' 60 supports an annular pad 61 of resilient material, such `a rubberlike or elastomeric material. The inner surface'of the annular-ringfl engages the outer periphery of the cylinder 42 and formsan air seal therewith. j'

As shown in Fig. Yl, the piston 23 is provided with an annular seat 62 that seats upon the upper surface of the resilient annulus61 whereby the piston-,23"is'supported by the cylinder 42 of the kshock absorber through the mediumof the resilient annulus.v It will'also be Vnoted that the structure just described provides for the movable walljof the air spring to be supported .by the Y'shock ab"- sorber upon the; lower-controlarm 12 through the'medium c absorber. v vThus, the shockl absorber 25 not only connects 3.7 that Vextends through the closed kend-38 of the shock f abs'orb'er .cylinder andiis provided yattachment vtting 39 securedioA vthe stationary walL 2 2fof/-the cone tai'ri'erl-.,1 ,-a suitablerubberlike rneinberl40, `or elastoe' merio member, .being positioned between the upper end -41lo'fthe rod 37 and l'the container-21;' whereby the rbd j 31 isresiliently movable relative tol the can 21 but'iirmly jedthereto. Y 1

r V'tened rigidly to the shockfabsorber.

` and therod seal for Ythe same.;Y

the lower- ,control armf127with the-chassisV frameA 102 for its normal purpose of absorption o f:shock andcontro1 of-re- Vboundpbut it also provides thesupport of themovable wall of theair spring irrits normal` functionf of resiliently supporting Vthe chassisframe 10 relativeto the ylower control arm.12. A. clearance VopeningrGS is'provided'in'the piston-'2 3 forming Vthemovablewall of-th'eairspring to allow for transversetmov/ement of the piston element relative tothe `shock absorber 25.' ,.1 s V50 rvIt will'be'appreciated thatintthe normal operation of the wheelsupport -system,-the'control arm 12;. as well as the control -arm16 move-in an arcuatefcourse relative to the chassisframe 10.- arcuate c ourseofmovement` transmitted to the movable wall 235 of the air sprng'would normally create transverse or lateral forces on the shock absorber 25 themovablewall of the air spring we'iefasvresult in.a' v high degreeofl friction injrnovement of the '60* shock absorber. piston 36 `.within its-'cylinder v35 and would produce undue strain antistress upon the shock absorber rod37thereby'V shortening the life oi the shock absorber However, placementof the r ilientnlbber-lilce elasto- '6"5, meric annulusVV `6 1 `between'thefpistonv 24 andthe shock 48 is rised'from'its seat;49 on movementV of the piston element A seating upon the re absorber allows y relative movementbetween Vthe-movable `=wall of the air `spring and the shock absorber so-that angu- Ylar deection between the movable 'all spring and thejshockabsorber be transnnttedltothe resilient elastomeric annulusA 61 and `therebyredu ce4 or eliminate the: transverse orf lateral forces ythat-*mightotherwise be :transmitted to the shoclgabsorber 25.

vIt will also be appreciated `tha airreal is 'provided to, pieve,

Such faction would the-:irirovableV wall Vsi-lijentfannulu's .61,.2111Y of airunder pressure 'l from within the container 21, the compression of the elastomeric member 61 by the weight of the vehicle creating a good air seal between the elastomeric member 61 and the seat 62, as well as with the outer periphery of the -shock absorber cylinder 42.

of, `an air spring comprising a hollow container having a stationary wall and a movable wall connected by a ilexible wall providing for relative movement between the stationary and movable walls, and a shock absorber unit positioned largely within said container connected between said stationary wall and said movable wall with a rilient pad on the shock absorber supporting the movable wall on the shock absorber unit with a nonrigid connection therebetween insulating transmission of angular displacement movement between the movable wall and the shock absorber.

2. An air suspension unit constructed and arranged in accordance with claim 1 wherein said resilient pad includes wall surfaces engaging said movable wall and said shock absorber unit forming uid seals thereby between the movable wall and the shock absorber unit to prevent escape of air from said container.

3, In an air suspension unit for supporting the sprung mass of a Vehicle on the unsprung mass, the combination of, an air spring comprising a hollow open-ended container, a wall at the open end of said container movable relative to the same and connected to the container by a tiexible wall providing for the said relative movement, and a shock absorber unit positioned within said container having one end thereof connected with said container and the opposite end connected with said wall with a resilient pad on the shock absorber supporting the said Wall on the shock absorber unit with a nonrigid connection therebetween insulating transmission of angular displacement movement between the wall and the shock absorber.

4. In an air suspension unit for supporting the sprung mass of a vehicle on the unsprung mass, the combination of, an air spring comprising a hollow open-ended container, a wall at the open end of said container movable relative to the same and connected to the container by a iiexible diaphragm wall providing for the said relative movement, a shock absorber comprising a cylinder and piston arrangement in which the piston reciprocates in said cylinder and rod means is attached to said piston with the rod means extending from the cylinder, said shock absorber member being positioned within said container with the cylinder or the rod part attached to said container and with the other of the respective parts extending through said wall, the other of said parts of said shock absorber supporting a resilient member on the exterior thereof, said resilient member supporting said movable wall on the exterior of said shock absorber with a nonrigid connection insulating angular displacement of the movable Wall from the shock absorber.

5. In an air suspension unit for supporting the sprung mass of a vehicle on the unsprung mass, the combination of, an air spring comprising a hollow container having a stationary wall and a -movable wall connected by a iiexible wall providing for relative movement between the stationary and movable walls, a shock absorber member comprising 'a cylinder and piston arrangement in which the piston reciprocates in said cylinder and a rod means is attached to said piston with the rod means ex- Y tending from one end of the cylinder, said shockV absorber member being positioned within said container with the said cylinder or the said rod meansl attached to said stationaryrwall and with the other of the parts of the shock absorber means extending through said movable wall for attachment to a part of the vehicle, and a resilient pad of elastomeric material carried on the exterior of the part of the shock absorber that extends through said movable wall, said movable wall being supported exteriorly of the shock absorber Von said pad providing thereby for relative angular displacement movement between the movable wall and theshock absorber member during movement of the movable wall relative to the stationary wall.

n 6. In an air suspension unit for supporting the sprung mass of a vehicle on the unsprung mass, the combination of, an air spring comprising a hollow container having a stationary wall and a movable wall connected by a tiexible Wall providing for relative movement between the stationary and movable walls, a direct-acting type shock absorber member comprising a cylinder and pistonparrangement in which the piston reciprocatesy in said cylinder and rod means is attached to said piston with the rod means extending from one end of the cylinder, said shock labsorber member being positioned within said container with the said cylinder or the said rod means attached to said stationary wall withthe other ofthe said parts of .the shock absorber extending through said movable wall,

an annular member of elastomeric material supported upon the exterior of said shock absorber part that extends through the said movable wall, the said movable wall being supported exteriorly of the shock absorber on the said annular member providing thereby for resilience of angular movement between the said movable Wall and the said shock absorber member and provide an air seal against loss of air from said container.

7. In an air suspension unit for supporting the sprung mass of a vehicle on the unsprung mass, the combination of, an air spring comprising a hollow open-ended container, a piston member at the open end of said container movable generally axially of the container and connected with the said open end thereof by a flexible diaphragm means adapted to conform to the exterior periphery of the and with the other of the parts of the said shock absorber extending through said first-mentioned piston member for attachment to a part of a vehicle, and a resilient elastomeric annular member carried on the part of the shock absorber that extends through said first-mentioned piston member supporting said first-mentioned piston member thereon exteriorly thereof and providing for resilience of angular movement between the said first-mentioned piston member and the said shock absorber.

8. An air suspension unit constructed and arranged in accordance with claim 7 wherein the said rst-mentioned piston member has a wall surface forming a seat engaged by a wall surface of the said elastomeric member forming thereby an air seal to prevent loss of air from the said container. v

9. In a suspension system for a motor vehicle, the combination, a chassis member, a movable member associated with a wheel system of the vehicle, said last-mentioned member being movable relative to said chassis member,

an air spring comprising a hollow container having a sta` tionary or movable walls secured to one of the said mern-V bers with the other of said stationary or movable walls positioned in close proximity to the other of the said members, a shock absorber unit comprising a cylinder and piston arrangement'in which the piston reicprocates in the cylinder partV and Vrod means attached to tbe Ypiston with the rod meansY extending from one end ofthe cylinder, said shocklabsrb'er member being disposed Within said VVcontainer with' the said cylinderpart or the said rod means thereof connected with one ofthe said stationary or mov- Yable Walls and 4the other Vof the said partsY extendingV Ythrough the other yof said ystationary ormovable walls ,andy connected lwith the -said` member that is in Vclose u,

resilient member to support'the same onthe said shock absorber parttht extends through the said movable wall solely by means of theV said 'resilient member. Y

' V11. YAV suspension system for a motor vehicle constructed and arranged in accordance with claim l() wherein the said resilient member comprises an l,annulus of elastomeric materialgwhich also forms an air seal preventing proximityl with` the said other Wa1l,.and an annulus `memi shockv absorber part extending through the said movable wall supporting the saidmvable wall on the exterior of Vthevs'a'idfshoek absorber part for resiliencer'of angular Y movement between the said movable Walland said shock [absorbenl 1,1 j

11).'A/si`1spensioi1V system for Ya, motor vehicle constructed and arranged in accordance with claim 9 wherein Vthe Said movable wall of said'co'ntainer comprises a piston movable into and out ofthe container', and wherein the V'bei"ofre'silientpmaterial carried onthe exterior ofthe saidv y exible wall comprises a exible diaphragm member that conforms to the exterior periphery ofthe just mentioned "pistonrmember on its movement into and outV of the said chamber, the just mentioned piston seating upon the said '25 Y Y l -escape of airrunder pressure from the said container.V

References Cited in thele of thisv patent ,Y UNITED STATES PATENTS 1,729,565 Carena; 1 ;V -f YSepe 24,V 1929y V2,134,072- Christensen Oct. 25,. 1938 2,393,493 Y Brown Jan.l 22, 1946 2,536,626 Coleman Jan. 2, 1951 ,Y 2,779,603 McRae Jan. 29, 1957 2,793,048 Adlol May 2l, 1957 2,893,104 vHancoek-.r July 7, 1959 2,916,296 1 Muller j l Dec. 8, 1959 r2,922,635 Y DeLorean Jan. 26, 196.0

f Y FOREIGN PATENTS )1,003,60s

Germany .Febl 28, 1957 

